"Google has released a research paper that suggests C++ is the best-performing programming language in the market. The internet giant implemented a compact algorithm in four languages - C++, Java, Scala and its own programming language Go - and then benchmarked results to find 'factors of difference'."

I think I can understand the rationale behind that decision : loop unrolling sounds like a rather costly optimization if mindlessly applied to all loops without PGO coming into play. But in this case, where PGO is not used, it indeed reduces the performance of the GCC binary.